The object of the proposed research is to delineate by anatomical methods the central vestibular pathways underlying the evoked potential data obtained during the first period of support. Projections from vestibular nuclei to thalamus, subcortical nuclei, and cortical areas I and II will be sought by anterograde and retrograde methods, employing horseradish peroxidase, tritiated proline, leucine, lysine, Fink-Heimer, and retrograde degeneration techniques.